Modern warfare’s devastation also brings the hidden dangers of unexploded weapons, landmines and booby traps. Who clears up the wreckage of natural and man-made catastrophes and where does it go?

Hurricanes Harvey, Irma and Maria battered the Caribbean and the southern US throughout the last two months, killing dozens, shattering lives and leaving a trail of destruction behind them.

Then, in the middle of September, a 7.1 magnitude earthquake hit central Mexico causing dozens of buildings to collapse in Mexico City and beyond, trapping people beneath broken concrete and twisted metal.

Who clears up the wreckage of natural and man-made catastrophes and where does it go?

Continuing conflicts in the Middle East have also left thousands dead and major cities destroyed. Much of Mosul in Iraq has also been reduced to rubble and huge swathes of Syria’s Homs and Raqqa and the World Heritage City of Aleppo have been flattened.

Aleppo's Old City has been devastated

The latest analysis of Aleppo, just completed by the UN’s satellite programme, UNOSAT, suggests more than 7,000 sites have been damaged in the Old City alone. Some witnesses describe rubble and wreckage piled to the top of buildings.

All these natural and man-made disasters have left behind millions of tonnes of debris. What will happen to it?